Silicone release agent and method

Abstract

A method of improving the release and antideposition characteristics of a hard impermeable surface. A hard impermeable surface is coated with a film of an aqueous solution. The solution is formed by combining (i) a dimer of at least two alkoxy functional silanes, (ii) an aqueous silicone emulsion of a polydiorganosiloxane, and (iii) water. The film is allowed to dry on the hard impermeable surface or the film can be wiped to dryness. The solution may also contain a water soluble hydrophilic solvent such as propylene glycol.

What is claimed is: 
     
       1. A release agent for improving the release and antideposition characteristics of a hard impermeable surface comprising an aqueous solution formed by combining (i) 1-5% by weight of a dimer of at least two alkoxy functional silanes, (ii) an aqueous silicone emulsion of a polydiorganosiloxane, the solution including 1-5% by weight of the polydiorganosiloxane, (iii) the total content of water in the solution being 60-98% by weight including the water of the emulsion; and (iv) 1-30% by weight of a water soluble hydrophilic organic solvent selected from the group consisting of ethylene glycol, propylene glycol, ethylene glycol n-butyl ether, ethylene glycol phenyl ether, diethylene glycol methyl ether, diethylene glycol n-butyl ether, propylene glycol methyl ether, propylene glycol methyl ether acetate, dipropylene glycol methyl ether acetate, propylene glycol n-butyl ether, propylene glycol phenyl ether, dipropylene glycol methyl ether, dipropylene glycol n-butyl ether, and tripropylene glycol methyl ether. 
     
     
       2. A release agent according to claim 1 in which one of the alkoxy functional silanes is an alkyltrialkoxysilane having C 1  to C 6  alkyl groups on silicon. 
     
     
       3. A release agent according to claim 2 in which the alkyltrialkoxysilane is a compound selected from the group consisting of methyltrimethoxysilane, ethyltrimethoxysilane, propyltrimethoxysilane, isopropyltrimethoxysilane, butyltrimethoxysilane, isobutyltrimethoxysilane, pentyltrimethoxysilane, and hexyltrimethoxysilane. 
     
     
       4. A release agent according to claim 2 in which the other alkoxy functional silane is a silane coupling agent having the formula X 3  Si(CH 2 ) n  Y in which n has a value of zero to three, X is a hydrolyzable group on silicon, and Y is a reactive organofunctional group. 
     
     
       5. A release agent according to claim 4 in which the silane coupling agent is a compound selected from the group consisting of N-(2-aminoethyl)-3-aminopropyltrimethoxysilane, N-(aminoethylaminomethyl)phenyltrimethoxysilane, N-(2-aminoethyl)-3-aminopropyltris(2-ethylhexoxy)silane, 3-aminopropyltrimethoxysilane, trimethoxysilylpropyldiethylenetriamine, propylmethylmethylphosphonate trimethoxysilane, sodium (trihydroxysilyl) propylmethylphosphonate, and bis(2-hydroxyethyl)-3-aminopropyltrimethoxysilane. 
     
     
       6. A release agent according to claim 1 in which the solution includes 15 to 20 percent by weight of the water soluble hydrophilic organic solvent.